1. Riina Klais PhD student (2008-2012) Tartu University (Estonia) Institute of Ecology and Earth Sciences Department of Nature and Technology Supervisor: Kalle Olli

2. Baltic Sea phytoplankton in a temporal shift Data: Since 1965, there have been ca 15 000 phytoplankton samples collected and analyzed during national monitoring programs. After extremely time consuming work over 40 years, and recent collection and harmonization of those varying data tables from different providers, we have 15 000 samples, with approximately 500 000 single records in a single table for comprehensive analysis of the trends and patterns in species composition in the Baltic Sea.

3. Data providers: Finnish Environment Institute (SYKE), Finland Finnish Environment Institute (SYKE), Finland Finnish Institute of Marine Research (FIMR), Finland Finnish Institute of Marine Research (FIMR), Finland Helsinki city, Finland Helsinki city, Finland Institute of Aquatic Sciences, Latvia Institute of Aquatic Sciences, Latvia Stockholm University, Sweden Stockholm University, Sweden Institut für Ostseeforschung Warnemünde (IOW), Germany Institut für Ostseeforschung Warnemünde (IOW), Germany National Environmental Research Institute (NERI), Denmark National Environmental Research Institute (NERI), Denmark Estonian Marine Institute, Estonia Estonian Marine Institute, Estonia HELCOM HELCOM

4. Data Not homogenous spatially Not homogenous in time

5. Synthesis Exercise no 1: Diatom / dinoflagellate rivalry in spring blooms. It has been suggested, that dinoflagellates are taking over spring blooms, and competing out the diatoms; Possible reasons: climate change – i.e. positive NAO indexes, resulting in milder winters, and early stratification in spring – giving the advantage to motile species (Wasmund and Uhlig, 2003); anthropogenic – i.e. decreasing concentration of silicate (Danielsson et al, 2008)?

6. Synthesis Problem 1: defining the spring samples biomass of the sample, timing (varies with latitude), proportion of diatoms/dinoflagellates, indicator species… Variable analysed: Proportion Dinophyceae = biomass Dinophyceae /(biomass Bacillariophyceae + biomass Dinophyceae )

7. Gulf of Finland

8. Bothnian bay and Bothnian Sea

9. Northern Baltic Proper + Archipelago sea, Gotland Basin + Gulf of Riga

10. Southern Baltic Proper, the Sound

12. Questions a) Is the rivalry between dinoflagellates and diatoms somehow affected by the climate change (NAO, ice cover etc) or chemical properties of Baltic Sea (decreasing silica content)? b) Is it general ‘dinos’ vs ‘diatoms’ trend, or, is it only one group (suspect is Woloszynskia/Scrippsiella family), that is colonizing in its own specific way new locales (without particular help from climate or human impact)? c) What do we loose/win, if we have dinoflagellates instead of diatoms in spring blooms?

13. Synthesis Exercise no 2: Late summer species composition. Preliminary results indicate, that most important factor in PC analysis is always time

14. About me Scientific interests: numerical ecology, statistical methods for analyzing ecological data phytoplankton ecology, drivers for changes in species composition and biodiversity in Baltic Sea BSc: (2005) “Heterotrophic nanoflagellates in microbial food web”

15. References 1. Å. Danielsson, L. Papush, L. Rahm, 2008. Alterations in nutrient limitations — Scenarios of a changing Baltic Sea. Journal of Marine Systems, 73: 263-283. 2. Wasmund, N., Uhlig,S., 2003. Phytoplankton trends in the Baltic Sea. ICES Journal of Marine Science, 60: 177-186. Thank you!